File IO is slow, you need to have a asyncappender between your application and file i/o.
-----Original Message----- From: 刘东 [mailto:[email protected]] Sent: Thursday, December 16, 2010 10:02 AM To: Log4J Users List Subject: Re: Re: performance problem in multithread environment tanks for you reply. I write test program to show my appliaction case. package com.iss.cnooc.test.ebank; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class LoggerTest { Logger logger = LoggerFactory.getLogger(LoggerTest.class); public static void main(String[] args) { int i = 0; while (i < 2) { LoggerThread t = new LoggerThread(); t.start(); i++; } } } package com.iss.cnooc.test.ebank; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class LoggerThread extends Thread { Logger logger = LoggerFactory.getLogger(LoggerThread.class); @Override public void run() { int i = 0; long start = System.currentTimeMillis(); while (i < 1000000) { logger.debug("i = " + i); i++; } long ecl = System.currentTimeMillis() - start; System.out.println(this.getName() + "-" + this.getId() + " spend " + ecl); } } The test reslut is thread number | cost 1 | 46859 2 | 96593 4 | 196921 16 | 717703 I use fileappender. why? 2010-12-16 刘东 发件人： Curt Arnold 发送时间： 2010-12-16 14:15:03 收件人： Log4J Users List 抄送： 主题： Re: performance problem in multithread environment On Dec 13, 2010, at 10:54 AM, Jacob Kjome wrote: > You will get better performance by not logging at all, no question. However, there are tuning possibilities. I see you mention "logger.info()". In production, I generally only have "warn()" and above for the vast majority of loggers. In fact, I configure the root logger up with the "WARN" level and selectively set other loggers to something less than WARN (if need be). > > The other thing you might look at is whether you are concatenating strings in your logging statements. For instance the following will incur an unnecessary cost in concatenating strings even when the "DEBUG" level is not enabled.... > > logger.debug("product: " + someProduct + ", price: " + somePrice); > > A more efficient way to define this in your code is.... > > if (logger.isDebugEnabled()) { > logger.debug("product: " + someProduct + ", price: " + somePrice); > } > alternatively use LogMF or LogSF (in the extras companion or in the SVN HEAD) LogMF.debug(logger, "product: {0}, price: {1}", price,somePrice); will have performance generally comparable to using logger.isDebugEnabled when logging is disabled since any conversion and concatenation is deferred until after the logging level is checked. --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
